Prepare inhibitors of chymotrypsin/elastase, pepsin, carboxypeptidases A and B, and trypsin from the same crude extract of Ascaris by using affinity chromatography. The preparations of inhibitors will be used to: a. Complete the primary sequence of Peak II and Peak IV Chymotrypsin/elastase inhibitors. b. Assign the disulfide bridge pairings in the chymotrypsin/elastase inhibitor. c. Locate the lysine residue(s) in Ascaris trypsin inhibitor which responds to maleoylation as if it were located in the P1 site. (Arginine was found in the P1, site.) d. Establish the conditions for crystallization of the pepsin-Ascaris pepsin inhibitor complex. d. Determine the primary structure of the Ascaris carboxypeptidase inhibitor. Determine whether the concentration of proteinase inhibitors in Ascaris eggs and larvae is correlated with stages in their biological development. Determine what happens to host proteolytic enzymes when they encounter live adult Ascaris. Establish whether Ascaris intestines have digestive enzymes that are capable of hydrolyzing host proteins. Determine how live Ascaris respond to lipase, amylase, ribonuclease and deoxyribonuclease, other host pancreatic enzymes, which are also present in their environment.